Reagent dipsticks and immunoassays have been used in medical clinics for decades in connection with methods for rapidly diagnosing health conditions at the point of care. Dipsticks have been used for the diagnosis of a number of conditions including urinary tract infections, preeclampsia, proteinuria, dehydration, diabetes, internal bleeding and liver problems.
Dipsticks are laminated sheets of paper containing reagents that change color when exposed to an analyte solution. Each reagent test pad on the dipstick is chemically treated with a compound that is known to change color in the presence of particular reactants. For example. in the context of a urinalysis, the dipstick will typically include reagent pads for detecting or measuring an analyte present in a biological sample of urine.
The magnitude of the color change of the reagent test pads is proportional to analyte concentration in the biological sample fluid. Dipsticks and their reagent test pad are typically manually interpreted with the naked eye by comparing the test strip against a colored reference chart. Such manual color comparisons can be imprecise for several reasons, including; changes in ambient lighting, subjective comparisons, and impaired color vision that a significant portions of the earth's population has.
It is desirable to improve upon manual color comparisons between reagent test pads and color reference charts.